This program focuses on the research into the effects of drugs on cancers in mice being conducted by the internationally renowned cancer team at Toronto's Princess Margaret Hospital. Written by the head of the team, Dr. Bob Bruce, who also appears on the program, the film begins with a human patient with a tumour which has passed beyond the stage where it can be treated by either surgery or radiation. At the end we see the patient again, after successful treatment with drugs. Also J.W. Meakin of the Princess Margaret Hospital appears.